Botatablb heab fob



eb. 3, 1931. w, MCNAUGHTON 1,790,829

ROTATABLE HEAD FOR RIVET SPINNING MACHINES Filed May 9, 1929 IN VENTOR.

A TTORNE YS.

Patented Feb. 3, 1 93 1 UNITED STATES WILLIAM B. MGNAUGHTON, or rArRrIE-Ln, conuno'rrcur, ASSIGNDRTO rnn'enAiir I MANUFACTURING AND MACHINE COMPANY, or iamnenroiar.mmnnorroun .con-

PORATION OF CONNECTICUT Ro'r 'rAnLE HEAD ron RIVE T SPINNING MACHINES Application filed May 9,

This invention relates to new-and useful improvements in rivet spinningmachin'es,

and more particularly to the spinning head .or tool, for forming heads upon rivet ends as in the act of rivetingtwo pieces of metal toconcaved and the smaller diameter end of the work to form a head upon the rivet.

' -My patent above referred to, like some other inventions for similar purposes, employs a pair of rollers in a holder for working upon the rivet head, both of said rollers being mounted upon the same horizontal bearing, though free to turn in opposite di rections. The theory of the action is to work on opposite edge portions of the rivet at the same time. I find with that form of spinning head the rollers, if not already separated, will in time separate, with respect to each other, and in operation consequently form a tit on the center of the top of the rivet head, being formed, and will thus not produce a smooth surfaced head, as is desired.

I have therefore'endeavored to overcome this difiiculty by using a relatively larger single roller whose diameter is greater through one side portion than the other and wherein the face of the larger diameter is is I straight, said .concaved surface merging and minor details of construction. within the scope of the claim may be. resorted to 1929. Serial no. se'1,e12.- 7

without departure from the spirit, or sacri ficing any. of the advantagesof the'inven tionp, I Similar characters of reference denote like or corresponding parts throughout the 4 Fig. 2 is a further central; vertical section through the spinning head, taken ata right angle to Fig.1.

- reference marked upon the drawings, -5 indi'- Referring in detail to' the characters of cates the holder having an upper annular shouldered portion Gffor the engagement of a wrench in the attachmentof the head to or removal of the head from a spindle,- not shown. The holder is further provided with a threaded recess 7 in its upper end portion for its attachment to the rotary spindle of a spinning machine, not shown. The

lower end portionof the holder is tapered inwardly and rounded to form a smooth end portion. -A transverse pocket 8 is formed 1 in the lower end portion of the holder, forming parallel smooth faced walls between which a roller 9 is rotatably mounted.

This roller is rotatably supported upon a screw 10 which passes through aligned transverse holes 11 and 12 of the two side members 13 and 14. The hole 11 serves to receive the head end of the screw and thethreaded hole 12 to receive the reduced threaded endof the screw, forretaining the same and the roller within the holder. at represents the larger port-ion or operative face of the roller, and 'b the smaller portion or inoperative face so that when-a rivet as indicated by dotted lines in Fig. 2, is being operated'upon, the operative face of the roller will operate upon the V entire end and head of the rivet. The roller may be so shaped and proportioned that substantially one half the face is concave and the remaining half of a lesser diameter,-in Cross section. It is important that the roller be positioned so' that the .center of its diamv :eter is in line with the axis of the holder which brings the larger diameter of the roller 7 to roll upon one side of the head only, thecenter of the head acting as an axis upon Which the roller spins. The-larger and curved portion of the roller serves first to break down the annular edge of the rivet and then spread the same out to form a relatively Wide rivet head of any desired size and proportion having a smooth rounded upper surface.- By using a single roller 1n th1s manner the forming of objectionable tits upon the top of the head is eliminated and the forming of a per feet head'is assured.

Having thus described myinvention, what I claim and desire to secure by Letters Patenu 1s:

In a spinning head for rivet spinning machines, a rotatable holder having a central longitudinal threaded hole for attachment to a vertical spindle; and having a central transverse opening,- forming opposite jaws, a bearing mounted in the anus a single roller, rotatably mounted Within the pocket and upon the bearing and having the center of its diameter in line With the axis of the rotatableholder, said roller being larger through one edge portion than the other and said larger portion having an annular concave surfacein cross section, the diameter of the other edge portion of the roller being uniform and having a straight smooth annular surface in cross section.

Signed at Bridgeport in the county of Fairfield and State of Connecticut this 7th day of May, A. D. 1929. r

WILLIAM B. MGNAUGHTON. 

